The role of gastropod shell composition and microstructure in resisting dissolution caused by ocean acidification
| Autor: | Stephen T. Packer, Murray K. Gingras, Lindsey R. Leighton, Kristina M. Barclay |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
0106 biological sciences
Gastropoda Shell (structure) Aquatic Science Oceanography 010603 evolutionary biology 01 natural sciences chemistry.chemical_compound Animal Shells Tegula funebralis Animals Seawater 14. Life underwater Nucella ostrina Dissolution Calcite biology Chemistry 010604 marine biology & hydrobiology Ocean acidification General Medicine Hydrogen-Ion Concentration biology.organism_classification Pollution Gastropod shell Calcium carbonate Solubility Chemical engineering |
| Zdroj: | Marine Environmental Research. 162:105105 |
| ISSN: | 0141-1136 |
| Popis: | Organisms, such as molluscs, that produce their hard parts from calcium carbonate are expected to show increased difficulties growing and maintaining their skeletons under ocean acidification (OA). Any loss of shell integrity increases vulnerability, as shells provide protection against predation, desiccation, and disease. Not all species show the same responses to OA, which may be due to the composition and microstructural arrangement of their shells. We explore the role of shell composition and microstructure in resisting dissolution caused by decreases in seawater pH using a combination of microCT scans, XRD analysis, and SEM imaging. Two gastropods with different shell compositions and microstructure, Tegula funebralis and Nucella ostrina, were exposed to simulated ocean acidification conditions for six months. Both species showed signs of dissolution on the exterior of their shells, but changes in density were significantly more pronounced in T. funebralis. XRD analysis indicated that the exterior layer of both shell types was made of calcite. T. funebralis may be more prone to dissolution because their outer fibrous calcite layer has more crystal edges and faces exposed, potentially increasing the surface area on which dissolution can occur. These results support a previous study where T. funebralis showed significant decreases in both shell growth and strength, but N. ostrina only showed slight reductions in shell strength, and unaffected growth. We suggest that microstructural arrangement of shell layers in molluscs, more so than their composition alone, is critical for determining the vulnerability of mollusc shells to OA. |
| Databáze: | OpenAIRE |
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